U.S. patent application number 14/288206 was filed with the patent office on 2015-01-01 for method of manufacturing liquid discharge head.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Kenji Fujii, Keisuke Kishimoto, Ryotaro Murakami, Masahisa Watanabe.
Application Number | 20150004724 14/288206 |
Document ID | / |
Family ID | 52115971 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150004724 |
Kind Code |
A1 |
Watanabe; Masahisa ; et
al. |
January 1, 2015 |
METHOD OF MANUFACTURING LIQUID DISCHARGE HEAD
Abstract
A method of manufacturing a liquid discharge head includes:
forming a first hole which penetrates through a wafer and becomes
at least part of a liquid supply port and a second hole which does
not penetrate through the wafer and becomes at least part of a
cut-off portion from a front side of the wafer; arranging a dry
film on the front side of the wafer; forming a flow passage forming
member by heating and developing the dry film; and cutting off the
liquid discharge head from the wafer by grinding the wafer from a
back side so that the second hole penetrates through the wafer.
Inventors: |
Watanabe; Masahisa;
(Yokohama-shi, JP) ; Fujii; Kenji; (Yokohama-shi,
JP) ; Kishimoto; Keisuke; (Yokohama-shi, JP) ;
Murakami; Ryotaro; (Yokohama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
52115971 |
Appl. No.: |
14/288206 |
Filed: |
May 27, 2014 |
Current U.S.
Class: |
438/21 |
Current CPC
Class: |
B41J 2/1631 20130101;
B41J 2/1639 20130101; B41J 2/1603 20130101; B41J 2/1628 20130101;
B41J 2/1629 20130101; B41J 2/1632 20130101 |
Class at
Publication: |
438/21 |
International
Class: |
B41J 2/16 20060101
B41J002/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2013 |
JP |
2013-136151 |
Claims
1. A method of manufacturing a liquid discharge head including a
substrate having a liquid supply port and a flow passage forming
member on a front side of the substrate, and configured to be
manufactured by being cut off from a wafer at a cut-off portion,
the method comprising: forming a first hole which penetrates
through a wafer and becomes at least part of the liquid supply port
and a second hole which does not penetrate through the wafer and
becomes at least part of the cut-off portion in the wafer from a
front side of the wafer; arranging a dry film on the front side of
the wafer so as to close the first hole and the second hole on the
front side; forming the flow passage forming member from the dry
film by heating and developing the dry film in a state in which the
first hole penetrates through the wafer; and cutting off the liquid
discharge head from the wafer by grinding the wafer from a back
side which is a side opposite to the front side so that the second
hole penetrates through the wafer.
2. The method of manufacturing a liquid discharge head according to
claim 1, wherein the first hole and the second hole are formed from
an opening in an etching mask formed on the front side of the
wafer, the substrate includes an energy-generating element, and the
etching mask covers the energy-generating element.
3. The method of manufacturing a liquid discharge head according to
claim 1, wherein the wafer is a silicon wafer formed of
silicon.
4. The method of manufacturing a liquid discharge head according to
claim 1, wherein the dry film is a negative photosensitive dry
film.
5. The method of manufacturing a liquid discharge head according to
claim 1, wherein the depth of the second hole falls within a range
from 50% to 95% of the depth of the first hole.
6. The method of manufacturing a liquid discharge head according to
claim 1, wherein the first hole and the second hole are formed from
the opening in the etching mask formed on the front side of the
wafer, the etching mask has an opening for forming the first hole
and an opening for forming the second hole, the opening area of the
opening for forming the first hole in the direction parallel to the
front surface of the substrate is larger than the opening area of
the opening for forming the second hole in the direction parallel
to the front surface of the substrate.
7. The method of manufacturing a liquid discharge head according to
claim 1, wherein the formation of the first hole and the second
hole is performed by reactive ion etching.
8. The method of manufacturing a liquid discharge head according to
claim 1, wherein the formation of the first hole and the second
hole is performed by wet etching.
9. The method of manufacturing a liquid discharge head according to
claim 4, wherein part of the dry film that closes the second hole
is not exposed.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This disclosure relates to a method of manufacturing a
liquid discharge head.
[0003] 2. Description of the Related Art
[0004] A liquid discharge head is used for a liquid discharge
apparatus such as an ink jet recording apparatus, and includes a
flow passage forming member and a substrate. The flow passage
forming member is provided on the substrate, has a liquid flow
passage formed therein and, in some cases, has a liquid discharge
port. The substrate has a liquid supply port, and liquid supplied
from the liquid supply port to the flow passage is discharged from
the liquid discharge port and lands on a recording medium such as
paper.
[0005] In general, such liquid discharge head (chip) as described
above is manufactured in such a manner that a plurality of liquid
discharge heads are manufactured simultaneously on one piece of
wafer, and the wafer is cut off along a cut-off portion into small
pieces of liquid discharge heads.
[0006] Japanese Patent Laid-Open No. 2010-162874 describes a
procedure of forming a liquid supply port and a cut-off portion in
the wafer by forming flow passage forming members on a front side
of a wafer (substrate) and etching the wafer from a back side.
[0007] Japanese Patent Laid-Open No. 2002-25948 describes a
procedure of forming a cut-off portion with holes by forming
members on a front side of a wafer, forming a non-penetrating hole
in the wafer between the members, and penetrating the
non-penetrating hole by grinding the wafer from a back side.
SUMMARY OF THE INVENTION
[0008] According to the disclosure, a method of manufacturing a
liquid discharge head is provided. The liquid discharge head
includes a substrate having a liquid supply port and a flow passage
forming member on a front side of the substrate and is configured
to be manufactured by being cut off from a wafer at a cut-off
portion. The method includes: forming a first hole which penetrates
through a wafer and becomes at least part of the liquid supply port
and a second hole which does not penetrate through the wafer and
becomes at least part of the cut-off portion in the wafer from a
front side of the wafer; arranging a dry film on the front side of
the wafer so as to close the first hole and the second hole on the
front side; forming the flow passage forming member from the dry
film by heating and developing the dry film in a state in which the
first hole penetrates through the wafer; and cutting off the liquid
discharge head from the wafer by grinding the wafer from a back
side which is a side opposite to the front side so that the second
hole penetrates through the wafer.
[0009] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a drawing illustrating an example of a liquid
discharge head manufactured in accordance with this disclosure.
[0011] FIGS. 2A to 2G are drawings illustrating an example of a
method of manufacturing the liquid discharge head of this
disclosure.
[0012] FIGS. 3A and 3B are drawings illustrating an example of the
method of manufacturing a liquid discharge head of this
disclosure.
[0013] FIGS. 4A and 4B are drawings illustrating an example of the
method of manufacturing the liquid discharge head.
DESCRIPTION OF THE EMBODIMENTS
[0014] According to the method described in Japanese Patent
Laid-Open No. 2010-162874, since a process (etching) of causing the
wafer to be penetrated from the front surface to the back surface
is performed after the formation of the flow passage forming
member, it takes a long time to process the wafer, and hence it is
necessary to sufficiently protect the flow passage forming member.
Therefore, longer manufacturing time and higher costs are required
correspondingly. According to the method disclosed in Japanese
Patent Laid-Open No. 2002-25948, since the holes are formed through
the wafer between the members, high degree of accuracy is required
in formation of the members and a high technology is required for
forming holes. Furthermore, when forming the holes for the cut-off
portion and the liquid supply port simultaneously, a higher
technology is required for the formation of the members and the
holes.
[0015] In order to solve the above-described problems, a method of
forming holes for the liquid supply port and the cut-off portion
from the front side of the wafer, and forming the flow passage
forming member on the front side after the formation of the holes
is conceivable. In this case, although the holes may be filled with
a material in order to prevent the flow passage forming member from
dropping into the formed holes, the filled material needs to be
removed later. Therefore, it is preferable to arrange a dry film
for closing the holes in order to prevent the flow passage forming
member from dropping into the holes instead of filling the holes
with the material, and utilize the dry film as a flow passage
forming member. The dry film arranged thereon has a flow passage
and a discharge port formed by, for example, a photolithography
process.
[0016] However, according to the study of the inventors of this
disclosure, it is found that when heating is performed in a post
exposure bake (PEB) process after the exposure in the
photolithography process, air in the hole (cavity portion), which
is sealed by the dry film, expands and hence affects the shape of
the flow passage forming member. This phenomenon will be described
with reference to FIGS. 4A and 4B. First, as illustrated in FIG.
4A, a hole 2 and a hole 3 are formed from a front side of a wafer
1, and a dry film 4 is arranged so as to close the holes. The hole
2 becomes at least part of the cut-off portion, and the hole 3
becomes at least part of the liquid supply port. The hole 2 and the
hole 3 form the sealed spaces by the arrangement of the dry film.
Subsequently, when the PEB process is performed, parts of the dry
film on the sealed spaces are deformed by the air expanded in the
sealed spaces, whereby deformed portions 5 are formed in the dry
film 4. In particular, since the deformed portion on the hole 3
serves as parts of the flow passage, the shape of the flow passage
forming member is deformed as a consequence. The heating process
may also be needed in processes other than the photolithography
process, and the heating process may cause deformation as described
above.
[0017] Accordingly, this disclosure aims to form a flow passage
forming member with high degree of accuracy even in the case of
forming the hole for the supply port and the hole for the cut-off
portion from the front side of the wafer, then forming the flow
passage forming member on the front side of the wafer by using a
dry film, and heating and developing the wafer.
[0018] Embodiments of this disclosure will be described below. FIG.
1 is a drawing illustrating an example of a liquid discharge head
manufactured in accordance with this disclosure. The liquid
discharge head includes a substrate 7 having a liquid supply port 6
and a flow passage forming member 8. The flow passage forming
member 8 is formed on a front surface 7a side of the substrate 7.
The liquid supply port 6 penetrates through the substrate from the
front surface 7a to a back surface 7b, which is a surface opposite
to the front surface. The substrate 7 is cut off from one piece of
wafer into individual substrates. The substrate 7 includes an
energy-generating element 9. Examples of the energy-generating
element 9 include an electrothermal conversion element and a
piezoelectric transducer. A control signal input electrode
configured to drive an energy-generating element is electrically
connected to the energy-generating element 9. The flow passage
forming member 8 is formed on the front side of the substrate 7 and
the flow passage forming member 8 forms a liquid flow passage 10.
The flow passage forming member 8 also forms a liquid discharge
port 11. Liquid supplied from the liquid supply port 6 to the flow
passage 10 receives energy from the energy-generating element 9,
and is discharged from the liquid discharge port 11.
[0019] A method of manufacturing the liquid discharge head will be
described with reference to FIGS. 2A to 2G. FIGS. 2A to 2G are
drawings illustrating cross-sectional views of a wafer including a
II-II cross section of the liquid discharge head in FIG. 1.
[0020] First, as illustrated in FIG. 2A, the substrate 7 provided
with the energy-generating element 9 on the front surface 7a side
is prepared. At this moment, the substrate is not cut off from the
wafer, and hence the substrate 7 is part of the wafer. The
substrate 7 is preferably a silicon substrate formed of silicon. In
this case, the wafer is a so-called silicon wafer. The silicon
substrate preferably has a crystal orientation of (100) on the
surface thereof. Alternatively, a silicon substrate having a
crystal orientation of (110) on the surface thereof.
[0021] Subsequently, as illustrated in FIG. 2B, an etching mask
layer 12 is formed on the front side of the wafer. The etching mask
layer may be formed of any material as long as it is hardly
disappeared by etching in comparison with the wafer and, for
example, is formed of SiN, SiC, SiCN, SiO.sub.2, or the like. The
etching mask layer is provided with an opening 12a and an opening
12b. The etching mask layer may be used as a protective layer or an
insulative layer that covers the energy generating element. In this
manner, the necessity of removing the etching mask layer is
eliminated. The protective layer and the insulative layer need not
to be provided separately. The opening 12a and the opening 12b are
formed, for example, by photolithography or reactive ion
etching.
[0022] Subsequently, as illustrated in FIG. 2C, the wafer is
processed from the opening 12a and the opening 12b, and a first
hole 13 and a second hole 14 are formed from the front side of the
wafer. The first hole 13 is formed from the opening 12a so as to
penetrate through the wafer from the front surface 7a to the back
surface 7b. The first hole 13 forms at least part of the liquid
supply port. The second hole 14 is formed from the opening 12b and
is not penetrated through the wafer. The second hole 14 forms at
least part of a cut-off portion. The cut-off portion is a portion
at a boundary along which the respective liquid discharge heads are
cut off from the wafer. Examples of the method of forming the first
hole and the second hole include reactive ion etching, wet etching,
and a mechanical process. The first hole and the second hole may be
formed using a combination of above-described methods. If the
second hole 14 is formed to be a hole penetrating through the wafer
at this time point, the liquid discharging head is easily separated
from the wafer in the process of forming the flow passage forming
member or in other processes, so that manufacture of the liquid
discharge head with high degree of accuracy becomes difficult.
[0023] The first hole and the second hole may be formed in the same
process. When the first hole and the second hole are formed by
reactive ion etching, the opening area of the opening 12a is
preferably larger than the opening area of the opening 12b in terms
of the opening area of the opening in the direction parallel to the
front surface of the substrate. With such a configuration, the
processing speed in the opening 12a is increased when the reactive
ion etching is performed simultaneously, and hence a relationship
that the first hole 13 penetrates through the wafer and the second
hole 14 does not penetrate through the wafer is easily
achieved.
[0024] Although the second hole does not penetrate through the
wafer, the depth thereof is preferably at least 50% of the
thickness of the wafer, that is, the depth of the first hole. If
the depth of the second hole is smaller than 50% of the thickness
of the wafer, the amount of time required for grinding the wafer
increases in later processes, and the manufacture of the liquid
discharge head is affected. More preferably, the depth of the
second hole is at least 60%, further preferably, at least 70% of
the thickness of the wafer. In order to maintain the strength of
the wafer at the time of the process, the depth of the second hole
is preferably not larger than 95% of the depth of the first hole.
If the depth of the second hole exceeds 95% of the depth of the
first hole, the thickness of the remaining part of the wafer at the
bottom of the second hole becomes extremely thin, and hence the
strength of the wafer is lowered, and the substrate probably
separates from the wafer. More preferably, the depth of the second
hole is not larger than 90%, further preferably, not larger than
80%.
[0025] The first hole and the second hole each may be formed
continuously, for example, in the longitudinal direction like a
groove. Alternately, the first holes and the second holes may be
formed discontinuously in the longitudinal direction. The same
applies to the width direction. If holes are formed
discontinuously, the holes may be connected later by etching.
[0026] Subsequently, as illustrated in FIG. 2D, a dry film is
arranged on the front side of the wafer where the first hole 13 and
the second hole 14 are formed on the front side of the wafer so as
to close the first hole 13 and the second hole 14. Furthermore, the
dry film is exposed by using a mask 15 and is heated (in the PEB
process), a latent image pattern is formed on the dry film. In
other words, heating of the dry film is performed in a state in
which the first hole 13 has penetrated through the wafer. The dry
film used here is a film in a dry state that is formed on a base
material such as polyester. After the dry film has transferred to
the wafer, the base material is removed. The dry film is preferably
a photosensitive dry film. In particular, the dry film is
preferably a dry film formed of a negative photosensitive resin.
Examples of the material of the dry film include an epoxy
resin.
[0027] A latent image pattern 4a on the dry film is a part that
closes the first hole 13, and is a part finally removed to form the
flow passage. A latent image pattern 4b is a part that closes the
second hole 14, and is a part removed finally and located above the
cut-off portion. A latent image pattern 4c is a part that becomes
part of the flow passage forming member 8. When the dry film is
heated in the PEB process, the latent image pattern 4b deforms as
illustrated in FIG. 2D. This is caused by expansion of air in the
second hole 14, which is a sealed space, located below the latent
image pattern 4b. However, that part is located above the cut-off
portion, and hence the expansion affects little on the shape of the
flow passage forming member. In contrast, deformation occurs little
on the latent image pattern 4a. This is because the first hole 13
located below the latent image pattern 4a penetrates through the
wafer, and hence is not a sealed space, so that air may be released
therefrom. Since a hole is substantially not formed below the
latent image pattern 4c, the latent image pattern 4c is little
subjected to deformation.
[0028] Part of the latent image pattern 4b, in other words, part of
the dry film which closes the second hole 14 is preferably not
cured by exposure. In the case where the dry film is a dry film of
negative type, the part of the dry film that closes the second hole
14 is preferably masked so as not to be exposed. If the part of the
dry film that closes the second hole 14 is cured, deformation may
affect the flow passage forming member in some cases.
[0029] Subsequently, as illustrated in FIG. 2E, a discharge port
forming member is formed on the dry film. The discharge port
forming member forms part of the flow passage, that is, an upper
wall of the flow passage in FIG. 2E. In other words, the discharge
port forming member in FIG. 2E is part of the flow passage forming
member. In FIG. 2E, the latent image pattern 4a remains without
being developed (removed), and the discharge port forming member is
formed thereon. However, the discharge port forming member may be
formed after the latent image pattern 4a is developed. A latent
image pattern 11a is formed on the discharge port forming member
by, for example, exposure. The latent image pattern 11a is a part
where a latent image of the shape of the discharge port is
formed.
[0030] The discharge port forming member is preferably formed of a
resin, and more preferably, formed of a photosensitive resin. The
discharge port forming member may be formed by spin coating or
direct coating, or may be stacked as a dry film on the dry film
located below. When exposing the discharge port forming member, the
sensitivity of the dry film located below and that of the discharge
port forming member need to be differentiated. In this case, the
discharge port forming member is preferably formed of a dry film.
Although the mode in which a discharge port forming member is
further formed has been described, a flow passage forming member
having a flow passage and a discharge port formed only with a
single dry film is also applicable.
[0031] When the discharge port forming member is heated, a deformed
portion 11b is formed. The deformed portion 11b is located above
the second hole 14, and is formed with deformation due to the
expansion of air in the second hole 14 or deformation of the latent
image pattern 4b. The deformed portion 11b is located above the
cut-off portion, and hence affects little the shape of the flow
passage forming member.
[0032] Subsequently, as illustrated in FIG. 2F, the latent image
pattern 4a, the latent image pattern 4b, the latent image pattern
11a, and the deformed portion 11b are removed. Accordingly, the
flow passage 10 and the liquid discharge port 11 are formed on the
flow passage forming member 8. Here, the example in which the
latent image pattern 4a, the latent image pattern 4b, the latent
image pattern 11a, and the deformed portion 11b are removed
simultaneously has been described. However, the latent image
pattern 4a, the latent image pattern 4b, the latent image pattern
11a, and the deformed portion 11b may be removed separately.
Alternatively, when the liquid discharge port 11 is formed not by
exposure or development, but by reactive ion etching or laser
irradiation, removal of the discharge port pattern is not
necessary.
[0033] In this stage as well, the first hole 13 penetrates through
the wafer, but the second hole 14 does not penetrate through the
wafer. Subsequently, as illustrated in FIG. 2G, the wafer is ground
from the back side so as to cause the second hole 14 to penetrate
through the wafer. Examples of a method of grinding include
mechanical grinding (CMP) or reactive ion etching.
[0034] When the second hole 14 penetrates through the wafer, a
portion including the second hole becomes the cut-off portion, so
that the liquid discharge head is allowed to be cut off from the
wafer at this portion. Simultaneously, the first hole 13 becomes
the liquid supply port 6. In FIG. 2G, the state in which two liquid
discharge heads are formed is illustrated.
[0035] As described above, according to this disclosure,
deformation of the flow passage forming member due to the expansion
of air in the sealed space is restricted, and the liquid discharge
head having the flow passage forming member with high degree of
accuracy is manufactured.
EXAMPLES
[0036] This disclosure will be described below further in detail by
using the examples.
Example 1
[0037] First, as illustrated in FIG. 2A, the substrate (wafer) 7
provided with the energy-generating element 9 on the front surface
7a side was prepared. The energy-generating element was made of
TaSiN, and a substrate, which was a silicon substrate, having a
crystal orientation of (100) was used as the substrate. The
thickness of the substrate was 700 m. Films of SiO.sub.2 and SiN
were formed on the energy-generating element by plasma CVD, and the
formed film was used as an insulating protection layer.
[0038] Subsequently, as illustrated in FIG. 2B, the etching mask
layer 12 was formed. The etching mask layer 12 was formed by using
a resin (product name: THMR-iP5700 HP, manufactured by TOKYO OHKA
KOGYO CO., LTD), so as to have a thickness of 10 m. Subsequently,
the opening 12a and the opening 12b were formed by photolithography
process. The opening width of the opening 12a was 100 m, and the
opening width of the opening 12b was 40 m in terms of the direction
parallel to the front surface of the substrate. The opening area of
the opening 12a was 10000 m.sup.2, and the opening area of the
opening 12b was 1600 m.sup.2 in terms of the direction parallel to
the front surface of the substrate.
[0039] Subsequently, as illustrated in FIG. 2C, the wafer was
processed by reactive ion etching from the opening 12a and the
opening 12b, and the first hole 13 and the second hole 14 were
formed from the front side of the wafer. Bosch process was employed
as the reactive ion etching, and the difference in etching rate
depending on the opening area was utilized, whereby the first hole
13 penetrating through the wafer and the second hole 14 which does
not penetrate through the wafer were formed simultaneously. The
depth of the first hole 13 was 700 m, which was the same as the
thickness of the wafer, and the depth of the second hole was 560
m.
[0040] Subsequently, as illustrated in FIG. 2D, a dry film was
arranged on the front side of the wafer where the first hole 13 and
the second hole 14 were formed so as to close the first hole 13 and
the second hole 14 on the front side of the wafer. A negative
photosensitive dry film containing an epoxy resin was used as the
dry film. Furthermore, by exposing the dry film by using the mask
15 and heating (PEB process) the same, a latent image pattern was
formed on the dry film. The exposure was conducted under the
conditions of an amount of exposure of 6000 J/m.sup.2, and heating
at 50.degree. C. for 5 minutes.
[0041] Subsequently, as illustrated in FIG. 2E, the discharge port
forming member was formed on the dry film. A negative
photosensitive dry film containing an epoxy resin was used as the
discharge port forming member. The discharge port forming member
was exposed and heated (PEB process), so that the latent image
pattern 11a was formed on the dry film. The exposure was conducted
under the conditions of an amount of exposure of 2000 J/m.sup.2,
and heating at 90.degree. C. for 4 minutes. At the time of heating
(PEB), the first hole 13 was in the state of penetrating through
the wafer.
[0042] Subsequently, as illustrated in FIG. 2F, the latent image
pattern 4a, the latent image pattern 4b, the latent image pattern
11a, and the deformed portion 11b were removed by melting with
propyleneglycol monomethylether acetate to form the flow passage 10
and the liquid discharge port 11 in the flow passage forming member
8.
[0043] Finally, as illustrated in FIG. 2G, the wafer is ground by
150 m from the back side by CMP so as to cause the second hole 14
to penetrate through the wafer. The portion including the portion
in which the second hole 14 penetrates through the wafer was used
as the cut-off portion, and the liquid discharge head was cut off
from the wafer at this portion.
[0044] The liquid discharge head was manufactured in the manner
described above. The manufactured liquid discharge head was
provided with the flow passage forming member formed with high
degree of accuracy.
Example 2
[0045] In Example 1, the first hole 13 and the second hole 14 were
formed by reactive ion etching as illustrated in FIG. 2C. In
Example 2, the first hole 13 and the second hole 14 were formed by
laser irradiation and wet etching instead of the procedure
illustrated in FIG. 2C. Description on parts which are the same as
those of Example 1 were herein omitted.
[0046] As illustrated in FIG. 3A, the substrate 7 was irradiated
with a laser from the opening 12a and the opening 12b, and the
first hole 13 and the second hole 14 were formed in the substrate
7. The irradiation with laser was performed using a third harmonic
(wavelength: 355 nm) of YAG laser at an output of 10W and a
frequency of 100 KHz. The first hole 13 was caused to penetrate
through the wafer, and the second hole 14 was not caused to
penetrate through the wafer. A plurality of the first holes 13 were
formed within the openings 12a, and one second hole 14 was formed
in the opening 12b.
[0047] Subsequently, as illustrated in FIG. 3B, the wafer was
subjected to wet etching with tetra-methyl-ammonium-hydride (TMAH)
having 22 mass % solution. The etching conditions were as follows;
an etching temperature of 83.degree. C., and an etching time of 2
hours. Even after the wet etching, the first holes 13 penetrated
through the wafer, and the second hole 14 did not penetrated
through the wafer.
[0048] In the same manner as Example 1 except for the points
described above, the liquid discharge head was manufactured. The
manufactured liquid discharge head was provided with the flow
passage forming member formed with high degree of accuracy.
[0049] According to this disclosure, even when the hole for the
supply port and the hole for the cut-off portion are formed from
the front side of the wafer, and then the flow passage forming
member is formed on the front side of the wafer by the dry film to
heat and develop the same, the flow passage forming member may be
formed with high degree of accuracy.
[0050] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0051] This application claims the benefit of Japanese Patent
Application No. 2013-136151, filed Jun. 28, 2013, which is hereby
incorporated by reference herein in its entirety.
* * * * *